The reason some people feel drunk before others is tied to the presence of a gene that is not present in others who react less strongly to alcohol according to a new study.

Researchers at the University of North Carolina believe 10% to 20% of people have a version of the gene that may offer some protection against alcoholism.

The study in the journal Alcoholism: Clinical and Experimental Research showed a variant in a gene called CYP2E1 is associated with response to alcohol.People who react strongly to alcohol are less likely to become addicted to the substance, studies have indicated.

"We have found a gene that protects against alcoholism, and on top of that, has a very strong effect," stated the study's author, Dr. Kirk Wilhelmsen, a professor of genetics at the University of North Carolina at Chapel Hill.

"But alcoholism is a very complex disease, and there are lots of complicated reasons why people drink," he added. "This may be just one of the reasons."

The researchers studied more than 200 pairs of college-age students who were siblings and had at least one parent who was an alcoholic.

Participants were given a mixture of grain alcohol and soda that was equivalent to about three average alcoholic drinks. They then were asked to describe how the alcohol made them feel, such as drunk or sleepy.

This revealed that CYP2E1 on chromosome 10 appears to dictate whether a person can hold their drink better than others.

According to Wilhelmsen, more research is required to determine if the findings could be used to make new treatments to tackle alcohol addiction.

The Alcoholism: Clinical and Experimental Research journal reported that people could be given CYP2E1-like drugs to make them more sensitive to alcohol and make them less likely to become addicted.